A replication technique for replicating data is known as a measure to protect against data loss. Among processes that use the replication technique are backup and disaster recovery (DR). A storage area in which data on an application is stored is called a data volume. Backup refers to the process of storing data in the data volume at a given point in time and storing it for a long period of time. DR refers to the process of constantly replicating data in the data volume so that the replicated data can be used in other systems.
Examples of replication include host-based replication performed on a host computer and array-based replication performed on a storage system.
In the host-based replication, Write data (data to be written) to be written to a data volume from an application is captured to create a replica volume that has stored therein the same data as the data volume. As the Write data from the application is written to a medium by transfer, the host-based replication can accommodate a heterogeneous environment without dependence on the storage devices. Further, the replica volume can be created at low cost.
In the array-based replication, a replica volume is created using a replication function of the storage. This allows creation of a replica volume that maintains the consistency among of a plurality of hosts without imposing load on the hosts.
As disclosed in Patent Document 1, there is known an environment that supports both host-based replication and storage-based replication. When such an environment is used, it is possible to effectively use their respective advantages. For example, when attempting to acquire backup data that maintains the consistency among a plurality of hosts, the administrator performs a backup operation using local-array-based replication. Meanwhile, when attempting to perform DR operation at low cost by utilizing the existing resources, the administrator would consider DR operation using host-based replication. As described above, an administrator who desires to perform an operation using both host-based replication and array-based replication is envisaged.
Patent Document 1: JP Patent Publication No. 2005-062928